CVE-2026-42346: medium-severity vulnerability in gitroomhq postiz-app
Postiz: TOCTOU DNS rebinding bypasses all SSRF URL validation paths
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.5epss 0.2%
Postiz is an AI social media scheduling tool. From version 2.16.6 to before version 2.21.7, all SSRF protections added in v2.21.4–v2.21.6 share a fundamental TOCTOU (Time-of-Check-Time-of-Use) vulnerability: isSafePublicHttpsUrl() resolves DNS to validate the target IP, but subsequent fetch() calls resolve DNS independently. An attacker controlling a DNS server can exploit this gap via DNS rebinding to redirect requests to internal network addresses. This issue has been patched in version 2.21.7.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
Affected products
gitroomhq · postiz-appRelated CVEs — gitroomhq postiz-app
In the same product, most dangerous first.
CVE-2026-19264CRITICALUnauthenticated arbitrary file read via /uploads path traversal (URL-encoded separators) leading to instance takeoverEPSS 1.0%CVE-2026-42298CRITICALPostiz: Arbitrary Code Execution and Token Exfiltration in pr-docker-build.yml via untrusted Dockerfile.devEPSS 0.5%CVE-2026-34577HIGHPostiz: Unauthenticated Full-Read SSRF via /public/stream Endpoint with Trivially Bypassable Extension CheckEPSS 0.5%CVE-2026-40168HIGHPostiz has Server-Side Request Forgery via Redirect Bypass in /api/public/streamEPSS 0.4%CVE-2025-53641HIGHPostiz allows header mutation in middleware facilitates resulting in SSRFEPSS 0.3%CVE-2026-34576HIGHPostiz: SSRF in upload-from-url endpoint allows fetching internal resources and cloud metadataEPSS 0.3%